Suction cup



FIG. 1 is a front right top perspective view of a suction cup showing my new design, the rear left top perspective view being an identical image thereof;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The evenly-sized broken lines shown in the drawings depict environment that forms no part of the claimed design.

The unevenly-sized broken lines define the bounds of the claimed design and form no part of the claimed design. 

CLAIM The ornamental design for a suction cup, as shown and described. 